Reflector.



A. AMES, JR. REFLECTOR.

APPLICATION FILED IAN. II, I9l6.

Patented Oct. 8, 1918 3 SHEETS SHEET. l.

A. AMES R, REFLECTOR.

APPLICATION FILED IAN-17,1916.

1,280,626. Patentd 00f. 8,1918. 7 3 SHEETS-SHEET'2.

A AMES, 1R.

REFLECTOR.-

APPLICAIION FILED JAN. 17. 1516.

Patent-ed 00. 8, 1918;

3 SHEETS-SHEET 3.

I ii; 7%. IO.

ADEELBER'I' AMES, JR., 0F TEWKESBURY, MASSACHUSETTS.

REFLECTOR.

Application filed January 17, 1916. Serial No, 72,504.

To all whom it may concern:

Be it known that I, AnnLBnnr'AMEs, J r., a citizen. of the United States, residin at lewkesbury, in the county of Midd eseX and State-of Massachusetts, have invented rertain new and useful Improvements in Reflectors, of which the following -1s a had' therein 1 specification, reference being to the accompanying drawings.

.\l v invention rclatesto hghts and lighting wherever control of radiant illuinina- (ion is desired, and pertains particularly to headlights such as are used on automobiles, interurban cars, and other vehicles.

The discomfort and danger caused to users of the highway by the use at night of ordinary headlightson vehicles is well known. There is also a considerable'inconvenience and danger to the driver of the vehicle.

The rays from a light source placed at the focus of the commonly used parabolic reflector go out in a bundle of parallel rays and light up the distant road, without lighting up, however, the road in the near or middle distance. It is a common practice of the users of such headlights to obtain illumination of the nearer parts of the road by putting the light source out of focus, either in front or behind, and thus change the reflected rays from a narrowparallel bundle to a broad diverging one. If the light source is put behind the focus, this effect is produced bv the rays striking the reflector at such an angle that they flare out directly, If the light source is put in front of the focus the rays strike the reflector at such an angle that they are reflected back across each other, and then flare out. The disadvantage of using such a diverging beam of light is: road is not properly illuminated and fast driving is very dangerous. 2nd. Part of the diverging bundle of rays radiate upward and are blinding to the other users of the highway, and are wasted for roadway illuminating purposes. If the light is put in the focus,'and the distant road illuminated, danger arises owing to the fact that the driver cannot see the near road.

- To meet these difflculties munerous States have passed laws requiring that the illumination from headlights shall radiate the light of the road in a predetermined inanner. 1 The object of the invention is to provide Specification of Letters Patent.

' a parabolic reflector combined with separate light sources, one at the focus, and the other 1st. That the distant Patented Oct. s, 1918.

a headlight which will do away with the above-mentioned dangers and nuisances,

utilize all of the radiant light energy and meet the different laws of the different States; for example, a headlight. 1st. 1" which will light up' the road at a distance as far as possible aheadof the car. 2nd, Which will light up all the road and sides of the road between such a distant pointdtifia anda point a few feet ahead of the car 3rd. lVhich will light up said road and sides of road to any extent and intensity. that may be required. 4th. To accomplish; the foregoing purposes in such amanner that no glareor blinding effect is caused to approaching pedestrians or drivers, or other users of the highway. 5th. To eon serve and utilize all of the radiant light' 'v energy of the lamp. a v

I accomplish these results by means of a reflector formed by the revolution of a suit able conic-section asha parabola or di. stantly focused ellipse; in fact any suitable operative structures,

Figure 1 is adiagrammaticelevation of q to the rear, and a shade to absorb light that would otherwise be reflected by' a portion f of the reflector. I Fig. 2 is a front view of the shade shown" in Fig. 1.

Fig. 3 isan elevation showing a contin--" -uons light source, a part of which only, is at the focus, and a shade to absorb unde-I sired rays afterreflection.

Fig. 4 shows separate light sources, one at the focus and the other in front of it, with shade andauxiliary-reflector. I

Fig. 5 a front view of shade and re flector shown in Fig. 4. I r

Fig. 6 is a view like Fig. 4, except the second source of light is at the rear of the focus and the shade and reflector are above the sources of light.

Fig. 7 is a front view of the shade and reflector appearing in Fig. 6. v

Fig. 8 shows a cylindrical electric light bulb having its sources of light like those in Fig. 6, combined with a reflector and shade above the light source so arranged as to allow light from the source at the focus and strike both halves of the parabolic reflector.

Figs. 9 and 10 are front "iews of the reflector and the shade shown in F ig. 8.

Fig. 11 is a diagrammatic view to illustrate why a source of light such as is obtainable placed at the focus of the reflector,

will not give a bundle of parallel rays.

Fig. 12 is a diagrammatic view of a parabolic reflector, having a cylindrical light bulb, and reflector, below its axis; one of its light sources being at the focus and the other in front of it.

Fig. 13 illustrates a particular form of light bulb, andthe astigmatic effect of a semi-cylindrical mirror, adapted to be used with a parabolic mirror.

Fig. 14 is like Fig. l, with the exception that it shows a mirror in the place of the shade, and the light source in focus slightly drawn back.

Fig. 15 shows a parabolic reflector,- a continuous source of light in a plane perpendicular to the axis of the mirror, and passing throughthe focus; the edge of the reflector being determined bysaid plane.

Fig. 16 is a view similar to Fig. 15; the plane passing through the focus of the refiector and containing the sources of light, being at an angle to the axis of the reflector.

I will now describe some of the various forms of structure embodying my invention.

An electric light 1. Fig. lfhaving two sources which are inclosed in a spherical bulb 2, is mounted at the apex of a parabolic reflector 3, so that-one source of light 4 is at the focus indicated by plane f, of the reflector, and the other in rear of the focus, at 5. A small screen 6 lies above the sources of light. Such a structure prevents all radiation of light from either source being reflected by the upper half of the reflector. Rays 7 from thesource 4 at the focus are deflected outwardly in a. parallel bundle that lights up the distant road without rising above the level of the top of the reflect-or; the lamp being assumed to'be mounted with the axis 88 of the reflector in a horizontal space between the bundle of parallel rays and a point a few feet in front of the car,

as is shown.

placed in the path of said rays 9' from source as 5, screen 10.

The prevention of the reflection in an undesirable direction, of the rays fronrthe source not in focus, can be accomplished by the proper placing of that source and the large reflector relative to each other.

If the reflector 3, Fig. 15, does not ex Fig. 3, after reflection, as a tend beyond a plane 14, passing through the focus 7", and the light sources not in focus, are placed in that plane, at 15, all rays 16 from 15, striking the reflector, will be reflected in the same direction relative to the axis 8 of the reflector, in this case downwardly. For the rays from 15 Will strike the upper half of the reflector as if they came from 17, in front of the focus f, and the lower half as if theycame from 18, behind the focus. Although in Fig. 15, the

plane 14 passing through the focus, is shown perpendicular to the axis 8, 8, it may. if desired, be at an angle with the axis; and, if the, refiector 3", Fig. 16, does not extend beyond= such plane la' and all of the light sources 15'- are situated in it, the resultant effect will be the same.

The light source 19, Fig. 4, not in focus. may be placed in front of the focus and when such is the case, a screen 20 ispIaced below it, as shown, which prevents the rays from both sources striking the lower half of the parabolic reflector; the rays 21 from the source 19. outside the focus f, strike only the upper half of the reflector, and being dcflected downwardly and outwardly, illuminate the road in the sameway as just described.

by making the inner face of the screen a properly shaped reflecting surface, for example, 6, Fig. 1, and 6, Fig. 6. The up wardly radiating rays 22 Fig. 6, instead of being absorbed, are reflected back to the lower half. of the parabolic reflector as if they had come from points 23, Fig. 6, inside the focus, and are by it reflected downwardly and outwardly. The intensity of the illumination is of course thus greatly increased.

A reflecting screen of any suitable shape "placedIthat"it'reflectsfallj'thiays'from one" or both sources, as theca's'e ,lfmy'bam one side 'or the other of theffocus asis desired; For some purposes, jthishrrangem'ent may l The arrangc'i'ncnt"that allows thelarger to 40% of the" incident light is absorbed by reflecting"surfaces, and there is therefore, l some loss in't he dtii' ble reflection of such rays", 22", FigQH; The arrangel'n'entin,Fig.'

Zond light-"source the bul 'lightffniustbe ,cylind J t 1 21f; Om ewer m dr he 1 larger thcspa'ce around f th jlight source in janj l'dnger the lamp "Willf lowly .ivill the "bulb can be used, cylindr cal, con cal, spherical,

be b'ettred by usinga smaller "screen 25, Fig. 8, and'25', Fig'flZ,'closetojtlie lainp 26',-2 as is respectively 'shdlv vn ,injFigs; '8 and 12..

The, advantagefof this, arijangem'ent is, that it allows a larger percentagejof rays, from the light source 4 at thej-focus, to strike" both halves of, ;and almost the' en'tiresurface of thaw-atone reflector '3 (seefrays 27, 28, 29,30, Fig. ,8, 31, 32, 33, 34, Fig.]12) and be projected outwardly with but onereflection; I V i i *een'can be placed he more" rays rom" The nearer 'tliesmall t i es i o 1 foc 1 the sourcea t bolicrcflc tor, at the same time p reflected from flect-onexjce t thatide 'd small screen as ni' "s that p tof rical and as ace the shape ofthe e s necessary percentage of the rays from th e lig ht source at thefocus. to be'pi'ojectecl outwardly with butfone, reflection, makes a somewhat more efficient light that inF-ig. '14." Fromfi ft l4, howeveig has anadvantagevover the ar- 'rahgcincnt. injFig. in that With proper focusing of tlie'light, no rays will be pro-- j ectetl above the axisipf I the reflector; While with the arrangement in- Fig. 8; no matter howthc light s focused, there will be.considerablcupwardly dlverg'in-grays. I

The reason for this is, that-"the most concentrated light sources are not points, but are of considerable-size, As a result. al-

/ though put exactly at the focus of a'parabolic reflector, certain rays Wi1lno't'g0 out in a parallel bundle, but Will diverge-upwardly and downwardly. For example, in Fig ll, rays 40 from points 41 on the light source which strike the reflector as if they had g-nme from points 4 outside of the focus f, Will follow the directions 41, 42, 40, both above T and below the axis, and after crossing the axis of the reflector at some distance in front, will diverge downwardly and up-.

rays from source not lILfQClls, fron being any' part; of the parabolic rebe winged? either above pr below.

strilge thereflec'to'r as if they had come from beh1n cl the focus, and will flare upwardly anddovvnwardly. This cannot be remedied by changing the'light source relative tot-he them, will flare out more broadly. If,--however; a screenior .a screen frefledtor, in this "foc'ti'sgforif it isdra-wn back so that rays [40 fror'n'i4l strike reflector as if theyhad' come from the focus, points 44 will bemore displaced than before, and'rays' 43 from casefaliemisphere' having itscenter' back of,

the focus, fispl'aced to properly prevent light from both sources striking one side of the parabolic reflector as in Fig; 14, the light source4 can be moved relatively to the focus f (in this case back) so that no rays will strike the parabolic'refiector as if they came fjfro r'n, points in front of the focus, and there-j r "fsultin'g i'flec'tedl'beain "will be composed of entirely parallel or downwardly deflecting rays; such an arrangement has the advantage 0f allowing the greatest elevation of the bannfand, thereforeythe greatest amount I of distant illumination with the least amount of glare.

l/Y lii le" a y complies vvith' the requirements already nien-' t1oned,f-w1 ll produceagood effect, for; still better control of" the illumination, it/iis '1 of' advantage to use a refiectmg screen tl at'will "gnean astigmati'c image of the light source f shapedrefiecting screen that as a seuii cylinder, or a semirsphere vithits y centeniiot at-oneof the-light sources. With a seinifcylindrical miner 45, FigllS," rays from any point in the light source 47 out'of tratech-light source to appear extended.

"focus; will follow both the lines '47, 48, 48,. ,49 and 47, 50,50, 51; Theeffect of there- I flections 211148 and 50 is to cause a conceni 1 Owing to this effect, the proper placii'i'g of a concentrated light source relative to "the small reflector 45, gives a result slnnlarto...

that produced with an extended light source, 1 0

The extent touvhich-the road and the sides of the -road,Wil-l beiHuminated can be controlled by-cha-nging the distanceback or -in"'. front of thefocu's. at hichrthe light source outof focus is placed. The intensity to which a particular part ofthe road is illumi-E nateclcan be controlled bychang'ing the intensity of the light source out of focus,'from one place to another in its length, or if it is a concentrated source,- its position relative. to the-reflector pr mirror placed close to it,

In allfthe above combinations, a small screen 52, Fig. 8, may be placed in front of the lamp to prevent direct outward and upward radiation from the light sources.

The sources of light may be separate sources as'4 and 5, Fig. 1; or a continuous source extending in and out of the focus as at 4 and 15, Fig..l5.' One source may be displaced from the focus, in front or behind 50 tance along a roadway, a Second light source,

-&

on the axis, as in Figs. 4 and 1; or itmay be placed (see Figs. 15 and 16) In any position relative to said focus 7, where raysfrorn it will strike one half of the parabohc reflector as 3, Fig. 15, as if they had come from a point or points 17 in front of the plane 14 perpendicular to the axis through said focus; the other half of the reflector, as if they had come from point or points 18 behind said plane. 1 f

It is to be understood that the words horizontal, vertical, u ward, downward, etc., are used throug out this specification and claims merely for convenience in referring to relative locations and directions,

, and that my invention is not limited to headnamely, that of adequately illuminating the roadway without producing upward glare, is attained without employing means to shield one-half of the reflector from the light and without employing means to obstruct light after being reflected upwardly. In Fig. 1, for example, if substantially the upper halfof the reflector is cut away or in anyway rendered inoperative, the reflector 6 flector having its focus substantially in said is not essential, although in the more specific aspect of the invention the reflector 1s 1mportant more completely to utilize the ra- 40 diant light. Likewise in Fig. 3, if the lower half of the deflector were eliminated the operation of the apparatus would be substantially the same as'when employing the obstruction 10.

WhatXI claim is:

1; Projection apparatus comprising a. light source, a substantially paraboloidal re:

I light source for-horizontally reflectin a concentra-ted beam of light a considera le the second light source being long andnarrow and being disposed along the axis of the reflector on one side of the focus, and a deflector arranged to deflect light emanating from said second source to the near portions and sides of the roadway.

2. Pro]ect10n apparatus comprising a light source, asubstantially paraboloidal rcflector having its focus substantially in said light source for horizontally reflecting a concentrated beam of light a considerable distance along a roadway, a' second light source, the second light source. being long on the cylindrical portions of said container so'as to deflect light emanating from said second source to the near portions and sides of the roadway.

3. Projection apparatus comprising a light source, a substantially paraboloida'l reflector having its focus substantially in said light source for horizontally reflecting a concentrated beam of light a considerable distance along a roadway, a second light source, the second light source being elongate and being disposed on one side of the focus substantially concentrically with the axis of said reflector, a transparent container for said light. sources, the container having a cylindrical portion concentric with said second light source, and a cylindrical deflector mounted on the cylindrical portion of said container concentric with said second light source so as to deflect the light emanating from said second source to the near portions and sides of the roadway.

4. Projection apparatus comprising a light source, a substantially paraboloida'l reflector having its focus substantially in the light source for horizontally reflecting a concentrated beam of light a considerable -distance along a roadway,.a second light source displaced from the focus, a transparent container for said light source, the container having substantially a cylindrical portion, and a substantially cylindrical deflector surrounding a portion of the cylindri'cal portion of the container for deflecting light to the reflector in such manner as to be reflected downwardly, whereby near, distant and intermediate portions of the roadway are illuminated without producing upward glare.

In testimony whereof -I hereunto aflix my signature in presence of two witnesses.

ADELBERT AMES, JR. Witnesses:

A. I. CRAWFORD, B. M. Snnon. 

